<?php
    // +----------------------------------------------------------------------
    // | ThinkPHP [ WE CAN DO IT JUST THINK ]
    // +----------------------------------------------------------------------
    // | Copyright (c) 2006~2017 http://thinkphp.cn All rights reserved.
    // +----------------------------------------------------------------------
    // | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
    // +----------------------------------------------------------------------
    // | Author: liu21st <liu21st@gmail.com>
    // +----------------------------------------------------------------------
    namespace think;

    use think\exception\ClassNotFoundException;

    class Loader {
        protected static $instance = [];
        // 类名映射
        protected static $map = [];
        // 命名空间别名
        protected static $namespaceAlias = [];
        // PSR-4
        private static $prefixLengthsPsr4 = [];
        private static $prefixDirsPsr4    = [];
        private static $fallbackDirsPsr4  = [];
        // PSR-0
        private static $prefixesPsr0     = [];
        private static $fallbackDirsPsr0 = [];
        // 自动加载的文件
        private static $autoloadFiles = [];

        // 自动加载
        public static function autoload($class) {
            // 检测命名空间别名
            if (!empty(self::$namespaceAlias)) {
                $namespace = dirname($class);
                if (isset(self::$namespaceAlias[$namespace])) {
                    $original = self::$namespaceAlias[$namespace] . '\\' . basename($class);
                    if (class_exists($original)) {
                        return class_alias($original, $class, false);
                    }
                }
            }
            if ($file = self::findFile($class)) {
                // Win环境严格区分大小写
                if (IS_WIN && pathinfo($file, PATHINFO_FILENAME) != pathinfo(realpath($file), PATHINFO_FILENAME)) {
                    return false;
                }
                __include_file($file);
                return true;
            }
        }

        /**
         * 查找文件
         * @param $class
         * @return bool
         */
        private static function findFile($class) {
            if (!empty(self::$map[$class])) {
                // 类库映射
                return self::$map[$class];
            }
            // 查找 PSR-4
            $logicalPathPsr4 = strtr($class, '\\', DS) . EXT;
            $first           = $class[0];
            if (isset(self::$prefixLengthsPsr4[$first])) {
                foreach (self::$prefixLengthsPsr4[$first] as $prefix => $length) {
                    if (0 === strpos($class, $prefix)) {
                        foreach (self::$prefixDirsPsr4[$prefix] as $dir) {
                            if (is_file($file = $dir . DS . substr($logicalPathPsr4, $length))) {
                                return $file;
                            }
                        }
                    }
                }
            }
            // 查找 PSR-4 fallback dirs
            foreach (self::$fallbackDirsPsr4 as $dir) {
                if (is_file($file = $dir . DS . $logicalPathPsr4)) {
                    return $file;
                }
            }
            // 查找 PSR-0
            if (false !== $pos = strrpos($class, '\\')) {
                // namespaced class name
                $logicalPathPsr0 = substr($logicalPathPsr4, 0, $pos + 1) . strtr(substr($logicalPathPsr4, $pos + 1), '_', DS);
            } else {
                // PEAR-like class name
                $logicalPathPsr0 = strtr($class, '_', DS) . EXT;
            }
            if (isset(self::$prefixesPsr0[$first])) {
                foreach (self::$prefixesPsr0[$first] as $prefix => $dirs) {
                    if (0 === strpos($class, $prefix)) {
                        foreach ($dirs as $dir) {
                            if (is_file($file = $dir . DS . $logicalPathPsr0)) {
                                return $file;
                            }
                        }
                    }
                }
            }
            // 查找 PSR-0 fallback dirs
            foreach (self::$fallbackDirsPsr0 as $dir) {
                if (is_file($file = $dir . DS . $logicalPathPsr0)) {
                    return $file;
                }
            }
            return self::$map[$class] = false;
        }

        // 注册classmap
        public static function addNamespaceAlias($namespace, $original = '') {
            if (is_array($namespace)) {
                self::$namespaceAlias = array_merge(self::$namespaceAlias, $namespace);
            } else {
                self::$namespaceAlias[$namespace] = $original;
            }
        }

        // 注册命名空间
        public static function register($autoload = '') {
            // 注册系统自动加载
            spl_autoload_register($autoload ?: 'think\\Loader::autoload', true, true);
            // 注册命名空间定义
            self::addNamespace([
                                   'think'    => LIB_PATH . 'think' . DS,
                                   'behavior' => LIB_PATH . 'behavior' . DS,
                                   'traits'   => LIB_PATH . 'traits' . DS,
                               ]
            );
            // 加载类库映射文件
            if (is_file(RUNTIME_PATH . 'classmap' . EXT)) {
                self::addClassMap(__include_file(RUNTIME_PATH . 'classmap' . EXT));
            }
            // Composer自动加载支持
            if (is_dir(VENDOR_PATH . 'composer')) {
                self::registerComposerLoader();
            }
            // 自动加载extend目录
            self::$fallbackDirsPsr4[] = rtrim(EXTEND_PATH, DS);
        }

        // 添加Ps0空间
        public static function addNamespace($namespace, $path = '') {
            if (is_array($namespace)) {
                foreach ($namespace as $prefix => $paths) {
                    self::addPsr4($prefix . '\\', rtrim($paths, DS), true);
                }
            } else {
                self::addPsr4($namespace . '\\', rtrim($path, DS), true);
            }
        }

        // 添加Psr4空间
        private static function addPsr4($prefix, $paths, $prepend = false) {
            if (!$prefix) {
                // Register directories for the root namespace.
                if ($prepend) {
                    self::$fallbackDirsPsr4 = array_merge((array)$paths, self::$fallbackDirsPsr4
                    );
                } else {
                    self::$fallbackDirsPsr4 = array_merge(self::$fallbackDirsPsr4, (array)$paths
                    );
                }
            } elseif (!isset(self::$prefixDirsPsr4[$prefix])) {
                // Register directories for a new namespace.
                $length = strlen($prefix);
                if ('\\' !== $prefix[$length - 1]) {
                    throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
                }
                self::$prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
                self::$prefixDirsPsr4[$prefix]                = (array)$paths;
            } elseif ($prepend) {
                // Prepend directories for an already registered namespace.
                self::$prefixDirsPsr4[$prefix] = array_merge((array)$paths, self::$prefixDirsPsr4[$prefix]
                );
            } else {
                // Append directories for an already registered namespace.
                self::$prefixDirsPsr4[$prefix] = array_merge(self::$prefixDirsPsr4[$prefix], (array)$paths
                );
            }
        }

        // 注册命名空间别名
        public static function addClassMap($class, $map = '') {
            if (is_array($class)) {
                self::$map = array_merge(self::$map, $class);
            } else {
                self::$map[$class] = $map;
            }
        }

        // 注册自动加载机制
        private static function registerComposerLoader() {
            if (is_file(VENDOR_PATH . 'composer/autoload_namespaces.php')) {
                $map = require VENDOR_PATH . 'composer/autoload_namespaces.php';
                foreach ($map as $namespace => $path) {
                    self::addPsr0($namespace, $path);
                }
            }
            if (is_file(VENDOR_PATH . 'composer/autoload_psr4.php')) {
                $map = require VENDOR_PATH . 'composer/autoload_psr4.php';
                foreach ($map as $namespace => $path) {
                    self::addPsr4($namespace, $path);
                }
            }
            if (is_file(VENDOR_PATH . 'composer/autoload_classmap.php')) {
                $classMap = require VENDOR_PATH . 'composer/autoload_classmap.php';
                if ($classMap) {
                    self::addClassMap($classMap);
                }
            }
            if (is_file(VENDOR_PATH . 'composer/autoload_files.php')) {
                $includeFiles = require VENDOR_PATH . 'composer/autoload_files.php';
                foreach ($includeFiles as $fileIdentifier => $file) {
                    if (empty(self::$autoloadFiles[$fileIdentifier])) {
                        __require_file($file);
                        self::$autoloadFiles[$fileIdentifier] = true;
                    }
                }
            }
        }

        // 注册composer自动加载
        private static function addPsr0($prefix, $paths, $prepend = false) {
            if (!$prefix) {
                if ($prepend) {
                    self::$fallbackDirsPsr0 = array_merge((array)$paths, self::$fallbackDirsPsr0
                    );
                } else {
                    self::$fallbackDirsPsr0 = array_merge(self::$fallbackDirsPsr0, (array)$paths
                    );
                }
                return;
            }
            $first = $prefix[0];
            if (!isset(self::$prefixesPsr0[$first][$prefix])) {
                self::$prefixesPsr0[$first][$prefix] = (array)$paths;
                return;
            }
            if ($prepend) {
                self::$prefixesPsr0[$first][$prefix] = array_merge((array)$paths, self::$prefixesPsr0[$first][$prefix]
                );
            } else {
                self::$prefixesPsr0[$first][$prefix] = array_merge(self::$prefixesPsr0[$first][$prefix], (array)$paths
                );
            }
        }

        /**
         * 导入所需的类库 同java的Import 本函数有缓存功能
         * @param string $class   类库命名空间字符串
         * @param string $baseUrl 起始路径
         * @param string $ext     导入的文件扩展名
         * @return boolean
         */
        public static function import($class, $baseUrl = '', $ext = EXT) {
            static $_file = [];
            $key   = $class . $baseUrl;
            $class = str_replace([
                                     '.',
                                     '#'
                                 ], [
                                     DS,
                                     '.'
                                 ], $class
            );
            if (isset($_file[$key])) {
                return true;
            }
            if (empty($baseUrl)) {
                list($name, $class) = explode(DS, $class, 2);
                if (isset(self::$prefixDirsPsr4[$name . '\\'])) {
                    // 注册的命名空间
                    $baseUrl = self::$prefixDirsPsr4[$name . '\\'];
                } elseif ('@' == $name) {
                    //加载当前模块应用类库
                    $baseUrl = App::$modulePath;
                } elseif (is_dir(EXTEND_PATH . $name)) {
                    $baseUrl = EXTEND_PATH . $name . DS;
                } else {
                    // 加载其它模块的类库
                    $baseUrl = APP_PATH . $name . DS;
                }
            } elseif (substr($baseUrl, -1) != DS) {
                $baseUrl .= DS;
            }
            // 如果类存在 则导入类库文件
            if (is_array($baseUrl)) {
                foreach ($baseUrl as $path) {
                    $filename = $path . DS . $class . $ext;
                    if (is_file($filename)) {
                        break;
                    }
                }
            } else {
                $filename = $baseUrl . $class . $ext;
            }
            if (!empty($filename) && is_file($filename)) {
                // 开启调试模式Win环境严格区分大小写
                if (IS_WIN && pathinfo($filename, PATHINFO_FILENAME) != pathinfo(realpath($filename), PATHINFO_FILENAME)) {
                    return false;
                }
                __include_file($filename);
                $_file[$key] = true;
                return true;
            }
            return false;
        }

        /**
         * 实例化（分层）模型
         * @param string $name         Model名称
         * @param string $layer        业务层名称
         * @param bool   $appendSuffix 是否添加类名后缀
         * @param string $common       公共模块名
         * @return Object
         * @throws ClassNotFoundException
         */
        public static function model($name = '', $layer = 'model', $appendSuffix = false, $common = 'common') {
            $guid = $name . $layer;
            if (isset(self::$instance[$guid])) {
                return self::$instance[$guid];
            }
            if (false !== strpos($name, '\\')) {
                $class  = $name;
                $module = Request::instance()->module();
            } else {
                if (strpos($name, '/')) {
                    list($module, $name) = explode('/', $name, 2);
                } else {
                    $module = Request::instance()->module();
                }
                $class = self::parseClass($module, $layer, $name, $appendSuffix);
            }
            if (class_exists($class)) {
                $model = new $class();
            } else {
                $class = str_replace('\\' . $module . '\\', '\\' . $common . '\\', $class);
                if (class_exists($class)) {
                    $model = new $class();
                } else {
                    throw new ClassNotFoundException('class not exists:' . $class, $class);
                }
            }
            self::$instance[$guid] = $model;
            return $model;
        }

        /**
         * 解析应用类的类名
         * @param string $module 模块名
         * @param string $layer  层名 controller model ...
         * @param string $name   类名
         * @param bool   $appendSuffix
         * @return string
         */
        public static function parseClass($module, $layer, $name, $appendSuffix = false) {
            $name  = str_replace([
                                     '/',
                                     '.'
                                 ], '\\', $name
            );
            $array = explode('\\', $name);
            $class = self::parseName(array_pop($array), 1) . (App::$suffix || $appendSuffix ? ucfirst($layer) : '');
            $path  = $array ? implode('\\', $array) . '\\' : '';
            return App::$namespace . '\\' . ($module ? $module . '\\' : '') . $layer . '\\' . $path . $class;
        }

        /**
         * 字符串命名风格转换
         * type 0 将Java风格转换为C的风格 1 将C风格转换为Java的风格
         * @param string  $name    字符串
         * @param integer $type    转换类型
         * @param bool    $ucfirst 首字母是否大写（驼峰规则）
         * @return string
         */
        public static function parseName($name, $type = 0, $ucfirst = true) {
            if ($type) {
                $name = preg_replace_callback('/_([a-zA-Z])/', function ($match) {
                    return strtoupper($match[1]);
                }, $name
                );
                return $ucfirst ? ucfirst($name) : lcfirst($name);
            } else {
                return strtolower(trim(preg_replace("/[A-Z]/", "_\\0", $name), "_"));
            }
        }

        /**
         * 实例化验证类 格式：[模块名/]验证器名
         * @param string $name         资源地址
         * @param string $layer        验证层名称
         * @param bool   $appendSuffix 是否添加类名后缀
         * @param string $common       公共模块名
         * @return Object|false
         * @throws ClassNotFoundException
         */
        public static function validate($name = '', $layer = 'validate', $appendSuffix = false, $common = 'common') {
            $name = $name ?: Config::get('default_validate');
            if (empty($name)) {
                return new Validate;
            }
            $guid = $name . $layer;
            if (isset(self::$instance[$guid])) {
                return self::$instance[$guid];
            }
            if (false !== strpos($name, '\\')) {
                $class  = $name;
                $module = Request::instance()->module();
            } else {
                if (strpos($name, '/')) {
                    list($module, $name) = explode('/', $name);
                } else {
                    $module = Request::instance()->module();
                }
                $class = self::parseClass($module, $layer, $name, $appendSuffix);
            }
            if (class_exists($class)) {
                $validate = new $class;
            } else {
                $class = str_replace('\\' . $module . '\\', '\\' . $common . '\\', $class);
                if (class_exists($class)) {
                    $validate = new $class;
                } else {
                    throw new ClassNotFoundException('class not exists:' . $class, $class);
                }
            }
            self::$instance[$guid] = $validate;
            return $validate;
        }

        /**
         * 数据库初始化 并取得数据库类实例
         * @param mixed       $config 数据库配置
         * @param bool|string $name   连接标识 true 强制重新连接
         * @return \think\db\Connection
         */
        public static function db($config = [], $name = false) {
            return Db::connect($config, $name);
        }

        /**
         * 远程调用模块的操作方法 参数格式 [模块/控制器/]操作
         * @param string       $url          调用地址
         * @param string|array $vars         调用参数 支持字符串和数组
         * @param string       $layer        要调用的控制层名称
         * @param bool         $appendSuffix 是否添加类名后缀
         * @return mixed
         */
        public static function action($url, $vars = [], $layer = 'controller', $appendSuffix = false) {
            $info   = pathinfo($url);
            $action = $info['basename'];
            $module = '.' != $info['dirname'] ? $info['dirname'] : Request::instance()->controller();
            $class  = self::controller($module, $layer, $appendSuffix);
            if ($class) {
                if (is_scalar($vars)) {
                    if (strpos($vars, '=')) {
                        parse_str($vars, $vars);
                    } else {
                        $vars = [$vars];
                    }
                }
                return App::invokeMethod([
                                             $class,
                                             $action . Config::get('action_suffix')
                                         ], $vars
                );
            }
        }

        /**
         * 实例化（分层）控制器 格式：[模块名/]控制器名
         * @param string $name         资源地址
         * @param string $layer        控制层名称
         * @param bool   $appendSuffix 是否添加类名后缀
         * @param string $empty        空控制器名称
         * @return Object|false
         * @throws ClassNotFoundException
         */
        public static function controller($name, $layer = 'controller', $appendSuffix = false, $empty = '') {
            if (false !== strpos($name, '\\')) {
                $class  = $name;
                $module = Request::instance()->module();
            } else {
                if (strpos($name, '/')) {
                    list($module, $name) = explode('/', $name);
                } else {
                    $module = Request::instance()->module();
                }
                $class = self::parseClass($module, $layer, $name, $appendSuffix);
            }
            if (class_exists($class)) {
                return App::invokeClass($class);
            } elseif ($empty && class_exists($emptyClass = self::parseClass($module, $layer, $empty, $appendSuffix))) {
                return new $emptyClass(Request::instance());
            }
        }

        /**
         * 初始化类的实例
         * @return void
         */
        public static function clearInstance() {
            self::$instance = [];
        }
    }

    /**
     * 作用范围隔离
     * @param $file
     * @return mixed
     */
    function __include_file($file) {
        return include $file;
    }

    function __require_file($file) {
        return require $file;
    }
